


Heat Wave

by Dirtyglass



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: AKA Byleth tops, Ashe Blushing Cause That's Good Shit, Choking, F/M, First Time, Fluff and Smut, Friends to Lovers, Light Dom/sub, Love Confessions, Making Out, Porn With Plot, Post-Time Skip, Spoilers, no beta we die like Glenn
Language: English
Status: Completed
Published: 2020-02-21
Updated: 2020-02-21
Packaged: 2021-02-27 06:41:25
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,363
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22442752
Author URL: https://archiveofourown.org/users/Dirtyglass/pseuds/Dirtyglass
Summary: A confession in the empty Cathedral of Garreg Mach leads to Byleth and Ashe sharing their first time together.Post time-skip, minor spoilers for Ashe's character arc.
Relationships: Ashe Duran | Ashe Ubert/My Unit | Byleth
Comments: 7
Kudos: 64





	Heat Wave

**Author's Note:**

> This takes place in the Golden Deer route, no real major spoilers for the route.

Nights in Fodlan gave Ashe a chance to recover from the unbearable heat that plagued during the day. The summertime back in Faerghus didn’t seem nearly as bad compared to Garreg Mach, despite Gaspard being as close as it was to the headquarters. Still, he was in the Church pew wiping sweat off the back of his neck beneath his hoodie. 

The weather had been worse this particular summer, causing Monks and Priests to turn in early after the services. The heavy garbs making them feel lethargic and desperate to change into lighter clothes. Which lead to the Cathedral being cleared out, Ashe sticking onto the pew and hands folded together in prayer.

The emptiness of the room almost made him feel closer to the Goddess. The moonlight and warm candles are the only source of light. Where the stained glass used to be, now lie rubble leftover from the battle that set everyone apart. 

It wasn’t until a shadow from the center of the aisle fell over him that he was drawn out of prayer. Had he been younger, he would have assumed a ghost came to eat his soul. It only happened to be his dear Professor stopped before him. In all honesty, she _was_ the closest thing to a ghost in his life, she’d risen from the destruction of Garreg Mach after five long years.

There wasn’t any doubt in his mind that he would have died in Valley of Torment had she not spared him. But this wasn’t the time to go down that train of thought, he was here, and she was smiling at him like back in their academy days.

“Late-night prayer session, Ashe?” She asked with a raise of her brow, moving to sit next to him in the pew.

“Yes, Professor. I take it you’re patrolling?”

She gave a nod of her head as her eyes followed to the center of the room, probably imagining what this place used to look like. 

That wasn’t what Ashe was focused on anymore, all his attention went to what the Professor was wearing. The summer uniform he’d seen students wear before was hugging her curves. Far too short to be wearing in a Church of all places, her legs were on full display as it rode up dangerously further. Why was she wearing that? Where did she even get it?

The collar of his shirt seemed to tighten around his neck, using one finger to curl under and loosen it as much as possible. It didn’t take much for Ashe to blush, and when he did, he looked like a tomato thanks to his pale skin. Maybe the Professor wouldn’t notice--she’d chalk it up to the heat of the daytime. 

Back in the academy days, there were many who had a crush on the young professor. Ashe among them, he’d always stare at with wide-eyes in battle. Wondering where she learned that or how she managed to take down groups of enemies as if it were nothing. Unlike others, he kept the crush wrapped tight to his heart, living his daydreams of being more than a student to her. Even after all this time he knew that the crush still lingered inside of him. 

He had to draw his eyes away, lest his mind give into the impure thoughts that were starting to fill it. “I wish I knew where my summer uniform went. The weather has been awful, what do you think, Professor?” A timid smile across his face, completely putting his foot in his mouth. _’What are you doing, Ashe?! Why are you drawing attention to it?_ ’ he chided himself. 

She drew her fingers through her green strands, pushing it back onto her shoulder before answering him. “It could be worse.” 

That was something that didn’t change over five years, Byleth wasn’t a huge talker and tended to keep her replies short. Not that Ashe found that to be a negative trait, he always liked that she listened to him ramble, nodding here and there to let him know that she was paying attention. 

There was something that did change within Byleth, her feelings for Ashe. There weren’t far apart in age back in the academy days, even Byleth got mistaken for a student before she started teaching. The boyish charm and earnest attitude he had drawn her instantly to him, he was so genuine towards everyone he talked to. At that time the budding feelings had to be put to a stop, she was his teacher, and she had to keep it at that. 

Now, he was older and more refined than before. His goal of becoming a Knight had taken his youthful charm and evolved it into something far more chivalrous. There was a confidence he had riding on a horse and wielding his bow when he went into battle. And how did all of this make Byleth feel once they were back together? Well, the budding emotions she’d bury deep were flourishing like the first day of Spring. 

So maybe when she choose to wear the summer uniform, she’d hoped Ashe would take notice of how she looked. That he’d look at her as beyond a Professor, instead as someone that had fought side-by-side with her. Someone who was close in age as him, who could have been a classmate had circumstances been different. 

Most of all, she wanted him to see her as “Byleth,” the person who enjoyed fishing and sparring in her free time. 

“Ashe, call me Byleth,” she spoke at last, changing the topic of uniforms in an instant.

His green eyes went wide for a half-second, wondering what brought up the sudden request. “I… I suppose I could, but Prof--I mean, Byleth…” he trailed off, the name felt unusual on his tongue. Years of referring to her as his teacher was going to be a hard habit to kick. “Why?”

The silence in the Cathedral seemed to draw out the pause painfully long, Ashe faintly heard the sounds of owls echoing in the background. 

“I want to be more than your teacher,” she said at last. Byleth wasn’t a nervous person usually, however, her fingers were stuck fiddling with the end of her skirt. 

Ashe blinked twice, his mouth agape at the Professor’s confession. “More? Like a life-long mentor? I’ll always look up to you and--” The rambling starting all over again.

Her fingers gripped harder onto the edge of her skirt, words weren’t her strongest suit. That was why she had been a mercenary. She was paid to act, not ask questions or investigate motives. Though now she wished she had spoken up more throughout her life, maybe then she’d be better prepared to confess how she felt to Ashe.

Byleth shook her head, placing her hand onto Ashe’s thigh to quell his long-winded spiel. That shut him up quickly, her hand burned through the thick material of his trousers. Ashe didn’t think it was possible for the collar of his shirt to feel tighter around his neck.

“I care for you deeply, Ashe,” she paused, eyes meeting his. There was no blank stare like the one she had when she first came to Garreg Mach. He was able to see every ounce of emotion in her serious eyes. “More than as a friend too.”

Ashe was waiting for Byleth to pinch his thigh, that way he could wake up from this dream. It felt unreal that she’d admit such feelings towards him. He was just… Ashe. The commoner who wanted to become a Knight to help people. He always looked at her with puppy dog eyes, the near Demi-God Professor who could take down enemies in a single slash. Byleth was considered out-of-reach to him. He always assumed she’d go with someone like Claude or Sylvain, guys who seemed confident; Or at least faked it well.

Here he was, with the one and only teacher he adored admitting to liking him. 

She was about to say his name again until he stammered out a response. “I didn’t think you’d ever like me in that manner,” he leaned forward in the pew, taking her hand between his own. “But I’m thankful, so thankful, Byleth,” he felt if he didn’t say it now, when would he ever get another chance to?

He continued, holding tighter to her hands, and shifting to face her better. “I’ll continue to say your name as long as your feelings last,” his eyes were determined. 

There it was, that genuine boy she met at the academy now a man who still kept to his core. Ashe didn’t realize that he too had helped her, he was a calm soul who could ease her mind. After the adrenaline of battles, she’d sit with her sword still in a death gripe and unable to blink away the sights of bodies she’d slain. Ashe would be there to pry the sword out of her hand and put a blanket over her shoulders. 

A closed-lip smile graced her face, squeezing his hand in return. 

“That would make me happy, Ashe.”

A wave of relief came over his body knowing that she felt the same as him. It came to his attention that he had been staring at her lips for a moment too long, as her lips curled into a smile. He felt like he could stand on the roof of the cathedral and shout out how happy he was to all of Fodlan, until Seteth would yell at him to get down from there. 

Ashe felt like he was on a roll now, and there was something he desperately wanted to ask her before the moment went away. “Can I kiss you?” his voice quiet, only to be heard by her alone in the open space. 

“Of course,” she leaned forward to close the space between the two. 

Ashe didn’t know what to expect upon kissing Byleth, her lips were soft and inviting in contrast to the hard lines of her body. Perhaps it was from the crest of flames she had, but Ashe was burning up more than he thought was possible. The simple kiss wasn’t enough to sate him, he had to kiss her again, weave his hand into the back of her hair and press their lips closer.

Now Byleth didn’t know either what to expect from Ashe, but he certainly wasn’t disappointing her. He went into every task with fervor, and this proved to be no different. Her arms winded around his neck, moving her legs to lay across his lap as he pulled her closer. He was a man with desires too, even if he kept them a secret. 

And Byleth welcomed them with open arms, opening her mouth to slip her tongue out and trace the bottom of his lip. Falling into a hot trance of teeth and tongue in the middle of a church. Ashe’s free hand had found its way onto her bare thigh, feeling the hard muscles beneath his gloves. How he wished he could chuck his gloves off and feel her skin. This would have to do, evident in the way Byleth seemed to melt into his embrace. 

It wasn’t until a moan left the back of her throat that the trance was broken, Ashe pulled back to see the professor’s hair disheveled. His ears turned red along with the rest of his face upon realizing that he was the cause of her flustered state. “M-Maybe we should continue this somewhere else?” Shyness filling him as if he wasn’t still gripping onto her thigh, he at least came to his senses that they were in fact in public.

Her fingers reached to tuck his hair back behind his ear, admiring the way the candles in the room illuminated his white strands. Despite the redness covering his features, Byleth always liked the freckles scattered across his cheeks. Truthfully, she didn’t want to move away but knew better than to test their luck here. 

“We can, you look like you’re going to pass out wearing all that,” she responded, eyeing the hoodie he had on. Those Faerghus folks couldn’t handle heat in the slightest. “I’ll be glad to help you,” words dripping with double meanings as she said it with a straight face.

“Professor!” Ashe blurted, knowing full well where his mind went. He didn’t think it was possible for his face to get any deeper in color.

Byleth didn’t bother correcting him, he’d get used to calling her by her name in time. A small laugh came from her, while she stood and adjusted the skirt of her uniform. Ashe was almost breathless looking at her in the dim light of the room. He understood why people looked to her for guidance, she almost looked like a Goddess herself with that color of hair. 

He knew he’d certainly worship her if she requested that of him.

That wasn’t what Byleth wanted however as she guided them towards her room. At the end of the day, she wanted him to see her as an equal. He was a commoner, but that never affected the way Byelth felt towards him. Though she couldn’t say she’d be opposed to seeing him on his knees for other purposes then pray. 

There were seldom times Ashe had gotten to see her room, he’d notice a basket of lost objects off to the side firstly. Some items he recognized belonged to people who were no longer on their side, maybe she hoped that someday she’d be able to return them? The solemn idea was cast aside once Byleth turned to face Ashe.

It dawned on him that the door had been locked shut, and now his back was against it with Byleth’s arm caging him in. He might be a few inches taller than her, but she’d be able to stare him down anyday. Her fingers slid to the center of his chest, undoing the first button on his coat and taking her time on the way down.

“I said I’d help you, relax,” her voice was too calm for the situation at hand. He’d be doing anything but that when she was finally done and pushing it open. He didn’t have any of his armor on so it slid off his shoulders without a hitch. His hoodie remained and he wasn’t sure if his heart was going to remain in his chest any longer. 

The courteous boy within him thanked her nonetheless, only able to watch while her fingers made quick work of the remaining top. “Uh, Byleth, could I help you also?” he asked, looking down at her long eyelashes, he’d never been this close to notice how pretty they were. 

“You don’t need to ask,” she promised, voice soft while she took off the final shirt. It didn’t come as any shock to her that he’d be hesitant, she knew that she’d need to give a little push to get him going. Maybe it was the teacher in her who felt the need for encouragement. 

With a earnest shake of his head, Ashe tossed his gloves off to the pile of clothes on the ground. “I hope you don’t mind if--” he paused to pick up Byleth under her bottom and carry to the bed. It would have been smooth had he not stumbled over a sword on the ground and landed on top of her. “Ah--Sorry! Are you--”

The question was left unfinished as he heard her laughing, so bright and clear. Not something heard often enough in his opinion. “I see you’re still working on your muscles,” she smiled, running a hand through his bangs and off his forehead. Cupping his cheek in her hand, her thumb drawing across it tenderly.

There was nothing but a smile on his face, mostly glad to see she wasn’t upset at him for ruining the mood. “I’ll train even harder.”

Going back to the task at hand, Ashe realized his face had been planted in her… Bosom. Despite her muscles and scars, there was one area where she was soft at. None of the novels he read could have compared to being this close to someone in the flesh. Nor could they prepare him on what to do next, as he struggled to decide how to go about it. 

_Quit overthinking, go with the flow!_ his mind chided him.

As if reading his mind, she spoke up, “Can you take care of my shirt?” 

A hurried ‘of course,’ and he took to unbuttoning the white blouse. He didn’t want to be like Sylvain and gawk at her openly, but it was a challenge when her chest spilled out the top. The small clothes she wore underneath barely did anything to cover her up. This was a million times better than anything he read, and found himself putting his lips onto her collar bone to kiss along it. His hands untucking the rest of her shirt while he mouthed along her sweet skin, moving down to kiss along her cleavage.

It seems like her guidance wasn’t necessary any longer as the tips of his hair tickled her chest, using her hand to push it back. He must have felt bold enough to suck at the edge of her bra, leaving a small mark in its place. His tongue quick to soothe over the spot before retracing his steps to kiss up her neck. He’d truthfully didn’t see her neck much, it was always covered by her white collar. Now it seemed like he couldn’t get enough of it, going as far to moan against it when she pulled at his hair.

“ _Oh_ ,” he said breathlessly, surprised by himself that he enjoyed the subtle pain. Byleth’s face was starting to take on a dusting of pink. The high-waisted skirt she wore was starting to feel unbearably tight on her skin. His reaction didn’t go unnoticed, in fact, she was storing that tidbit well into her head. This time grabbing a fistful of his soft strands and pulling his neck head back to look her in the eyes. The tightness forming in his pants seemed to leap at the action, utterly smitten at the women before him. 

She used the moment to flip their positions, sitting on top of him and smiling down. Her hands reached behind her back to undo the strings keeping her bra on. The garment was tossed aside without a care, the fullness of her chest on full display for the man below her.

Ashe wasn’t one to swear using the Goddess’s name, however, this was a special occasion.

“You’re beautiful. I mean, you’re always beautiful I simply mean--” vomiting up words seemed to be his new budding talent. 

“I know what you mean,” Byleth hushed him with a smirk, her hand sliding up the center of his bare chest. Pulling it away to work the buttons of her skirt and have it join the growing pile of clothes. 

Ashe’s eyes went impossibly wide when there was nothing underneath the skirt. That entire time she hadn’t been wearing anything under the short heam. Meaning she went to the Cathedral like that and must have planned to some degree that the night would go like this. All of a sudden a lot of dots were connecting in his head.

Worst of all? He’d gotten harder than he thought was ever possible, and she by all means could feel that sitting on top of him. Even his dear teacher had a devious side. There wasn’t time to question her choice as she’d move to remove the pants he wore. The novels he read always had the man taking the lead, yet Ashe didn’t mind in the slightest that she took charge. His thoughts were becoming more and more clouded as his desire gew. 

It was like a mist had filled his head, she was moving back on top of him and putting a single hand around his neck. An unsaid question in the air as he nodded to give her the okay, he’d let her do whatever she wanted to him. Byleth was enamored with the man underneath her, glowing in the candle light of the room. A beautiful sight with her hand around his throat, the image of a fallen angel flashed in her head. 

A squeeze of her fingers suppressed his breathing briefly, her free hand tracing down his sharp hip bone towards his length. It was the perfect size to her, she wouldn't voice it aloud that she thought it was cute like him. Wrapping her fingers around its base, she started to stroke him slowly, and watched his expression. His eyes started to fall shut in bliss, the fog was overcoming all his senses. It was only those two together at this moment, Byleth’s devotion to him was all that mattered.

She was careful to make sure he wasn't pushing his limits too fast, too soon. His hand wrapped around the hand on his throat, anything that would tether him to this world. The simple actions she did caused him to pant heavily, small pleas with her name echoed within the room as she squeezed him harder. Occasionally pausing to let him catch his breath, only for him to grip her arm tighter and beg to continue. 

“Please,” he whimpered, his cock was painfully swollen. Red and aching at her ministrations, beads of pre-cum falling between her fingers. 

“I would never deny you,” she replied. “Although I’ll decide when,” twisting her wrist around him, watching droplets of sweat slide down his cheeks.

Ashe felt like he could burst, yet that would mean ending this all too soon. What strength he had left would have to do. The hand gripping his throat made it an enjoyable challenge, and he could tell Byleth enjoyed testing what he could handle. There was something he noticed a while ago, the wet heat coating his thighs the longer they played this little game. 

A sudden shift drew his eyes back open, Byleth covered his mouth with her own, and kissed him hard. Nothing like the sweet first kiss they had, it was open mouthed and panting into him like it was the last kiss they were ever going to share. Her wet heat grinded against the underside of his cock, seeking out that friction that made her toes curl. 

His arms wrapped around her waist, arching her back out and chest in. Momentarily wondering how he managed to get this far with a woman like Byleth. Yup, he was going to be on cloud nine for a while. His hips sought out the slick friction, coating his length easily and drawing him all the closer to release. 

She spoke against his lips, “Can I?” asking at last before going any further.

Once again he pleaded, “Please, Byleth, you’re torturing me.” A smile across his face, the warmth of his voice made her stomach leap.

The slide into her was too easy, so warm as his hands gripped onto her hip bones. The slow rise and fall of her hips made him erupt into a chorus of moans. The feelings were new and all consuming, the ease of her movements causing him to tremble. Byleth angled it the way she wanted, hitting the spot that would even break her cool exterior. 

The sweet friction electried her senses, she started to notice things that couldn’t be seen with his clothes on. The dusting of freckles across his chest, his shoulders had gotten broader and more muscled. Holding her closer against him, the heat of the room became unbearable to her as it filled her stomach. The rhythm she kept started to fall apart as her high drew closer, squeezing him tighter to urge him closer as well.

Ashe hated to admit that he wasn’t going to last long, but it became impossible at a particularly hard thrust. There wasn’t a chance to warn her, but Ashe suspected that she knew it was coming when her lips sealed against his. His nails tug into her hips as her name left in broken gasps, final, short thrusts into her heat caused him to empty out into her. 

“I told you I would decide,” she said against his ear, biting onto the shell of it. Rutting against him to finish herself and legs trembling against his waist as she neared. Now she was the one breathless, strands of hair falling across her face as the high overwhelmed her body. Laying against him with half-hearted movements to draw it out.

Ashe could have gotten hard again simply watching her get off, as that was a sight he knew he wasn’t going to tire of anytime soon. His hand found the hair against the back of her neck and moved it to the side to help her cool off. 

A few moments of silence filled the room before Ashe spoke up, “Thank you.” Her eyes looked up to him, pressed against his side now.

It might have been the post-orgasm high speaking, but Ashe felt the need to thank her. “I’m glad that it was with you,” he continued.

She raised an eyebrow in response, “It was your first time?”

“It was, have you..?” he asked without finishing the question, somehow managing to feel nervous even after what they did together. 

Her hand moved onto his chest, feeling his heartbeat quicken underneath it. 

“No, no one has been before you,” Byleth replied. “I should thank you.”

It was funny to Ashe, neither of them had bothered to ask if they’d been with anyone else. Neither of them were worried about such a thing, only that that it had been the right thing for both of them.

“You don’t need to do that, let me hold onto you longer,” his hand covering hers, his nose nuzzled into her hair. This closeness they shared would be more than enough for him and it was for her too. 

“Byleth, Byleth, Byleth…” he hummed quietly into her hair, feeling out the name on his tongue. “I don’t think I’ll ever get tired of saying it,” smiling as she tucked closer against him.

**Author's Note:**

> The night Ashe discovered a lot of kinks.
> 
> I'm heavily Claude biased, but damn, Ashe has my entire heart since he's so so so cute.
> 
> If you enjoyed this work, please leave a comment! Thanks for reading!


End file.
